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authorQi Wang <qiwan@redhat.com>2020-06-16 14:22:05 -0400
committerQi Wang <qiwan@redhat.com>2020-06-19 09:40:13 -0400
commitf61a7f25a8a6ec27fec069989f4b19b2ea19fc75 (patch)
tree6e6065b6a5456c66116ebc5c4bec7395df4bac5c
parent5ec29f8d4e79500915ec79824d9eb21630205f3f (diff)
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Add --preservefds to podman run
Add --preservefds to podman run. close https://github.com/containers/libpod/issues/6458 Signed-off-by: Qi Wang <qiwan@redhat.com>
-rw-r--r--cmd/podman/common/create_opts.go1
-rw-r--r--cmd/podman/common/specgen.go1
-rw-r--r--cmd/podman/containers/run.go3
-rw-r--r--completions/bash/podman1
-rw-r--r--docs/source/markdown/podman-run.1.md4
-rw-r--r--libpod/container.go5
-rw-r--r--libpod/oci_conmon_linux.go24
-rw-r--r--libpod/options.go12
-rw-r--r--pkg/domain/entities/containers.go1
-rw-r--r--pkg/specgen/generate/container_create.go4
-rw-r--r--pkg/specgen/specgen.go5
-rw-r--r--test/e2e/run_test.go12
-rw-r--r--test/system/030-run.bats12
13 files changed, 84 insertions, 1 deletions
diff --git a/cmd/podman/common/create_opts.go b/cmd/podman/common/create_opts.go
index 49052704e..4f3b8b322 100644
--- a/cmd/podman/common/create_opts.go
+++ b/cmd/podman/common/create_opts.go
@@ -69,6 +69,7 @@ type ContainerCLIOpts struct {
PIDsLimit int64
Pod string
PodIDFile string
+ PreserveFDs uint
Privileged bool
PublishAll bool
Pull string
diff --git a/cmd/podman/common/specgen.go b/cmd/podman/common/specgen.go
index e6a524358..599e003e8 100644
--- a/cmd/podman/common/specgen.go
+++ b/cmd/podman/common/specgen.go
@@ -609,6 +609,7 @@ func FillOutSpecGen(s *specgen.SpecGenerator, c *ContainerCLIOpts, args []string
}
s.LogConfiguration.Options = logOpts
s.Name = c.Name
+ s.PreserveFDs = c.PreserveFDs
s.OOMScoreAdj = &c.OOMScoreAdj
if c.Restart != "" {
diff --git a/cmd/podman/containers/run.go b/cmd/podman/containers/run.go
index b9c196b64..cb307c38f 100644
--- a/cmd/podman/containers/run.go
+++ b/cmd/podman/containers/run.go
@@ -61,10 +61,12 @@ func runFlags(flags *pflag.FlagSet) {
flags.SetNormalizeFunc(common.AliasFlags)
flags.BoolVar(&runOpts.SigProxy, "sig-proxy", true, "Proxy received signals to the process")
flags.BoolVar(&runRmi, "rmi", false, "Remove container image unless used by other containers")
+ flags.UintVar(&runOpts.PreserveFDs, "preserve-fds", 0, "Pass a number of additional file descriptors into the container")
if registry.IsRemote() {
_ = flags.MarkHidden("authfile")
_ = flags.MarkHidden("env-host")
_ = flags.MarkHidden("http-proxy")
+ _ = flags.MarkHidden("preserve-fds")
}
// Not sure we want these exposed yet. If we do, they need to be documented in man pages
_ = flags.MarkHidden("override-arch")
@@ -163,6 +165,7 @@ func run(cmd *cobra.Command, args []string) error {
}
runOpts.Detach = cliVals.Detach
runOpts.DetachKeys = cliVals.DetachKeys
+ cliVals.PreserveFDs = runOpts.PreserveFDs
s := specgen.NewSpecGenerator(args[0], cliVals.RootFS)
if err := common.FillOutSpecGen(s, &cliVals, args); err != nil {
return err
diff --git a/completions/bash/podman b/completions/bash/podman
index 5e990ec41..595739abf 100644
--- a/completions/bash/podman
+++ b/completions/bash/podman
@@ -2103,6 +2103,7 @@ _podman_container_run() {
--pids-limit
--pod
--pod-id-file
+ --preserve-fds
--publish -p
--pull
--runtime
diff --git a/docs/source/markdown/podman-run.1.md b/docs/source/markdown/podman-run.1.md
index 7e91a06a3..88666d595 100644
--- a/docs/source/markdown/podman-run.1.md
+++ b/docs/source/markdown/podman-run.1.md
@@ -609,6 +609,10 @@ If a container is run with a pod, and the pod has an infra-container, the infra-
Run container in an existing pod and read the pod's ID from the specified file. If a container is run within a pod, and the pod has an infra-container, the infra-container will be started before the container is.
+**--preserve-fds**=*N*
+
+Pass down to the process N additional file descriptors (in addition to 0, 1, 2). The total FDs will be 3+N.
+
**--privileged**=**true**|**false**
Give extended privileges to this container. The default is **false**.
diff --git a/libpod/container.go b/libpod/container.go
index 20702903e..c85249676 100644
--- a/libpod/container.go
+++ b/libpod/container.go
@@ -418,6 +418,11 @@ type ContainerConfig struct {
// HealthCheckConfig has the health check command and related timings
HealthCheckConfig *manifest.Schema2HealthConfig `json:"healthcheck"`
+
+ // PreserveFDs is a number of additional file descriptors (in addition
+ // to 0, 1, 2) that will be passed to the executed process. The total FDs
+ // passed will be 3 + PreserveFDs.
+ PreserveFDs uint `json:"preserveFds,omitempty"`
}
// ContainerNamedVolume is a named volume that will be mounted into the
diff --git a/libpod/oci_conmon_linux.go b/libpod/oci_conmon_linux.go
index 625a5bf70..d8a89047e 100644
--- a/libpod/oci_conmon_linux.go
+++ b/libpod/oci_conmon_linux.go
@@ -904,6 +904,10 @@ func (r *ConmonOCIRuntime) createOCIContainer(ctr *Container, restoreOptions *Co
}
}
+ if ctr.config.PreserveFDs > 0 {
+ args = append(args, formatRuntimeOpts("--preserve-fds", fmt.Sprintf("%d", ctr.config.PreserveFDs))...)
+ }
+
if restoreOptions != nil {
args = append(args, "--restore", ctr.CheckpointPath())
if restoreOptions.TCPEstablished {
@@ -935,8 +939,16 @@ func (r *ConmonOCIRuntime) createOCIContainer(ctr *Container, restoreOptions *Co
return err
}
+ if ctr.config.PreserveFDs > 0 {
+ for fd := 3; fd < int(3+ctr.config.PreserveFDs); fd++ {
+ cmd.ExtraFiles = append(cmd.ExtraFiles, os.NewFile(uintptr(fd), fmt.Sprintf("fd-%d", fd)))
+ }
+ }
+
cmd.Env = r.conmonEnv
- cmd.Env = append(cmd.Env, fmt.Sprintf("_OCI_SYNCPIPE=%d", 3), fmt.Sprintf("_OCI_STARTPIPE=%d", 4))
+ // we don't want to step on users fds they asked to preserve
+ // Since 0-2 are used for stdio, start the fds we pass in at preserveFDs+3
+ cmd.Env = append(cmd.Env, fmt.Sprintf("_OCI_SYNCPIPE=%d", ctr.config.PreserveFDs+3), fmt.Sprintf("_OCI_STARTPIPE=%d", ctr.config.PreserveFDs+4))
cmd.Env = append(cmd.Env, conmonEnv...)
cmd.ExtraFiles = append(cmd.ExtraFiles, childSyncPipe, childStartPipe)
cmd.ExtraFiles = append(cmd.ExtraFiles, envFiles...)
@@ -1018,6 +1030,16 @@ func (r *ConmonOCIRuntime) createOCIContainer(ctr *Container, restoreOptions *Co
ctr.state.ConmonPID = conmonPID
}
+ if ctr.config.PreserveFDs > 0 {
+ for fd := 3; fd < int(3+ctr.config.PreserveFDs); fd++ {
+ // These fds were passed down to the runtime. Close them
+ // and not interfere
+ if err := os.NewFile(uintptr(fd), fmt.Sprintf("fd-%d", fd)).Close(); err != nil {
+ logrus.Debugf("unable to close file fd-%d", fd)
+ }
+ }
+ }
+
return nil
}
diff --git a/libpod/options.go b/libpod/options.go
index ffc9c1018..7a60870a0 100644
--- a/libpod/options.go
+++ b/libpod/options.go
@@ -1369,6 +1369,18 @@ func WithHealthCheck(healthCheck *manifest.Schema2HealthConfig) CtrCreateOption
}
}
+// WithPreserveFDs forwards from the process running Libpod into the container
+// the given number of extra FDs (starting after the standard streams) to the created container
+func WithPreserveFDs(fd uint) CtrCreateOption {
+ return func(ctr *Container) error {
+ if ctr.valid {
+ return define.ErrCtrFinalized
+ }
+ ctr.config.PreserveFDs = fd
+ return nil
+ }
+}
+
// WithCreateCommand adds the full command plus arguments of the current
// process to the container config.
func WithCreateCommand() CtrCreateOption {
diff --git a/pkg/domain/entities/containers.go b/pkg/domain/entities/containers.go
index b4d8e6c29..9ea572293 100644
--- a/pkg/domain/entities/containers.go
+++ b/pkg/domain/entities/containers.go
@@ -294,6 +294,7 @@ type ContainerRunOptions struct {
ErrorStream *os.File
InputStream *os.File
OutputStream *os.File
+ PreserveFDs uint
Rm bool
SigProxy bool
Spec *specgen.SpecGenerator
diff --git a/pkg/specgen/generate/container_create.go b/pkg/specgen/generate/container_create.go
index 2f7100e7e..ea6f938a8 100644
--- a/pkg/specgen/generate/container_create.go
+++ b/pkg/specgen/generate/container_create.go
@@ -104,6 +104,10 @@ func MakeContainer(ctx context.Context, rt *libpod.Runtime, s *specgen.SpecGener
return nil, err
}
+ if s.PreserveFDs > 0 {
+ options = append(options, libpod.WithPreserveFDs(s.PreserveFDs))
+ }
+
opts, err := createContainerOptions(ctx, rt, s, pod, finalVolumes, newImage)
if err != nil {
return nil, err
diff --git a/pkg/specgen/specgen.go b/pkg/specgen/specgen.go
index bb01a5d14..c8fe49ec9 100644
--- a/pkg/specgen/specgen.go
+++ b/pkg/specgen/specgen.go
@@ -130,6 +130,11 @@ type ContainerBasicConfig struct {
// Remove indicates if the container should be removed once it has been started
// and exits
Remove bool `json:"remove"`
+ // PreserveFDs is a number of additional file descriptors (in addition
+ // to 0, 1, 2) that will be passed to the executed process. The total FDs
+ // passed will be 3 + PreserveFDs.
+ // set tags as `json:"-"` for not supported remote
+ PreserveFDs uint `json:"-"`
}
// ContainerStorageConfig contains information on the storage configuration of a
diff --git a/test/e2e/run_test.go b/test/e2e/run_test.go
index c78c23b1f..7e79a8668 100644
--- a/test/e2e/run_test.go
+++ b/test/e2e/run_test.go
@@ -1015,4 +1015,16 @@ USER mail`
Expect(session.ExitCode()).To(Equal(0))
}
})
+
+ It("podman run --preserve-fds", func() {
+ devNull, err := os.Open("/dev/null")
+ Expect(err).To(BeNil())
+ defer devNull.Close()
+ files := []*os.File{
+ devNull,
+ }
+ session := podmanTest.PodmanExtraFiles([]string{"run", "--preserve-fds", "1", ALPINE, "ls"}, files)
+ session.WaitWithDefaultTimeout()
+ Expect(session.ExitCode()).To(Equal(0))
+ })
})
diff --git a/test/system/030-run.bats b/test/system/030-run.bats
index aa9ace332..eeecea2e5 100644
--- a/test/system/030-run.bats
+++ b/test/system/030-run.bats
@@ -61,6 +61,18 @@ echo $rand | 0 | $rand
is "$tests_run" "$(grep . <<<$tests | wc -l)" "Ran the full set of tests"
}
+# 'run --preserve-fds' passes a number of additional file descriptors into the container
+@test "podman run --preserve-fds" {
+ skip "enable this once #6653 is fixed"
+ skip_if_remote
+
+ content=$(random_string 20)
+ echo "$content" > $PODMAN_TMPDIR/tempfile
+
+ run_podman run --rm -i --preserve-fds=2 $IMAGE sh -c "cat <&4" 4<$PODMAN_TMPDIR/tempfile
+ is "$output" "$content" "container read input from fd 4"
+}
+
@test "podman run - uidmapping has no /sys/kernel mounts" {
skip_if_rootless "cannot umount as rootless"
skip_if_remote "TODO Fix this for remote case"